<!DOCTYPE html>
<html>
    <head>
        <title></title>
        <meta charset="utf-8">
        <script language="JavaScript">
            expr = "4 * 250 + 8";	// 数学表达式
            n = eval(expr);	
            document.write(expr + " = " + n);	
        </script>
    </head>
    <body>
        
    </body>
</html>